2 * linux/include/linux/ext2_fs.h
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/include/linux/minix_fs.h
13 * Copyright (C) 1991, 1992 Linus Torvalds
16 #ifndef _LINUX_EXT2_FS_H
17 #define _LINUX_EXT2_FS_H
19 #include <ext2fs/ext2_types.h> /* Changed from linux/types.h */
22 * The second extended filesystem constants/structures
26 * Define EXT2FS_DEBUG to produce debug messages
31 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
33 #define EXT2_PREALLOCATE
34 #define EXT2_DEFAULT_PREALLOC_BLOCKS 8
37 * The second extended file system version
39 #define EXT2FS_DATE "95/08/09"
40 #define EXT2FS_VERSION "0.5b"
43 * Special inode numbers
45 #define EXT2_BAD_INO 1 /* Bad blocks inode */
46 #define EXT2_ROOT_INO 2 /* Root inode */
47 #define EXT4_USR_QUOTA_INO 3 /* User quota inode */
48 #define EXT4_GRP_QUOTA_INO 4 /* Group quota inode */
49 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
50 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
51 #define EXT2_RESIZE_INO 7 /* Reserved group descriptors inode */
52 #define EXT2_JOURNAL_INO 8 /* Journal inode */
53 #define EXT2_EXCLUDE_INO 9 /* The "exclude" inode, for snapshots */
54 #define EXT4_REPLICA_INO 10 /* Used by non-upstream feature */
56 /* First non-reserved inode for old ext2 filesystems */
57 #define EXT2_GOOD_OLD_FIRST_INO 11
60 * The second extended file system magic number
62 #define EXT2_SUPER_MAGIC 0xEF53
65 #define EXT2_SB(sb) (&((sb)->u.ext2_sb))
67 /* Assume that user mode programs are passing in an ext2fs superblock, not
68 * a kernel struct super_block. This will allow us to call the feature-test
69 * macros from user land. */
70 #define EXT2_SB(sb) (sb)
74 * Maximal count of links to a file
76 #define EXT2_LINK_MAX 65000
79 * Macro-instructions used to manage several block sizes
81 #define EXT2_MIN_BLOCK_LOG_SIZE 10 /* 1024 */
82 #define EXT2_MAX_BLOCK_LOG_SIZE 16 /* 65536 */
83 #define EXT2_MIN_BLOCK_SIZE (1 << EXT2_MIN_BLOCK_LOG_SIZE)
84 #define EXT2_MAX_BLOCK_SIZE (1 << EXT2_MAX_BLOCK_LOG_SIZE)
86 #define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
87 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
88 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->addr_per_block_bits)
89 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
90 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
92 #define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
93 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
94 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
95 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
96 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
97 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
99 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(__u32))
102 * Macro-instructions used to manage allocation clusters
104 #define EXT2_MIN_CLUSTER_LOG_SIZE EXT2_MIN_BLOCK_LOG_SIZE
105 #define EXT2_MAX_CLUSTER_LOG_SIZE 29 /* 512MB */
106 #define EXT2_MIN_CLUSTER_SIZE EXT2_MIN_BLOCK_SIZE
107 #define EXT2_MAX_CLUSTER_SIZE (1 << EXT2_MAX_CLUSTER_LOG_SIZE)
108 #define EXT2_CLUSTER_SIZE(s) (EXT2_MIN_BLOCK_SIZE << \
109 (s)->s_log_cluster_size)
110 #define EXT2_CLUSTER_SIZE_BITS(s) ((s)->s_log_cluster_size + 10)
113 * Macro-instructions used to manage fragments
115 * Note: for backwards compatibility only, for the dump program.
116 * Ext2/3/4 will never support fragments....
118 #define EXT2_MIN_FRAG_SIZE EXT2_MIN_BLOCK_SIZE
119 #define EXT2_MAX_FRAG_SIZE EXT2_MAX_BLOCK_SIZE
120 #define EXT2_MIN_FRAG_LOG_SIZE EXT2_MIN_BLOCK_LOG_SIZE
121 #define EXT2_FRAG_SIZE(s) EXT2_BLOCK_SIZE(s)
122 #define EXT2_FRAGS_PER_BLOCK(s) 1
127 struct ext2_acl_header /* Header of Access Control Lists */
130 __u32 aclh_file_count;
131 __u32 aclh_acle_count;
132 __u32 aclh_first_acle;
135 struct ext2_acl_entry /* Access Control List Entry */
138 __u16 acle_perms; /* Access permissions */
139 __u16 acle_type; /* Type of entry */
140 __u16 acle_tag; /* User or group identity */
142 __u32 acle_next; /* Pointer on next entry for the */
143 /* same inode or on next free entry */
147 * Structure of a blocks group descriptor
149 struct ext2_group_desc
151 __u32 bg_block_bitmap; /* Blocks bitmap block */
152 __u32 bg_inode_bitmap; /* Inodes bitmap block */
153 __u32 bg_inode_table; /* Inodes table block */
154 __u16 bg_free_blocks_count; /* Free blocks count */
155 __u16 bg_free_inodes_count; /* Free inodes count */
156 __u16 bg_used_dirs_count; /* Directories count */
158 __u32 bg_exclude_bitmap_lo; /* Exclude bitmap for snapshots */
159 __u16 bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
160 __u16 bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
161 __u16 bg_itable_unused; /* Unused inodes count */
162 __u16 bg_checksum; /* crc16(s_uuid+group_num+group_desc)*/
166 * Structure of a blocks group descriptor
168 struct ext4_group_desc
170 __u32 bg_block_bitmap; /* Blocks bitmap block */
171 __u32 bg_inode_bitmap; /* Inodes bitmap block */
172 __u32 bg_inode_table; /* Inodes table block */
173 __u16 bg_free_blocks_count; /* Free blocks count */
174 __u16 bg_free_inodes_count; /* Free inodes count */
175 __u16 bg_used_dirs_count; /* Directories count */
176 __u16 bg_flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */
177 __u32 bg_exclude_bitmap_lo; /* Exclude bitmap for snapshots */
178 __u16 bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
179 __u16 bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bitmap) LSB */
180 __u16 bg_itable_unused; /* Unused inodes count */
181 __u16 bg_checksum; /* crc16(sb_uuid+group+desc) */
182 __u32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */
183 __u32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */
184 __u32 bg_inode_table_hi; /* Inodes table block MSB */
185 __u16 bg_free_blocks_count_hi;/* Free blocks count MSB */
186 __u16 bg_free_inodes_count_hi;/* Free inodes count MSB */
187 __u16 bg_used_dirs_count_hi; /* Directories count MSB */
188 __u16 bg_itable_unused_hi; /* Unused inodes count MSB */
189 __u32 bg_exclude_bitmap_hi; /* Exclude bitmap block MSB */
190 __u16 bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bitmap) MSB */
191 __u16 bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bitmap) MSB */
195 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END \
196 (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
198 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION \
199 (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
202 #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */
203 #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */
204 #define EXT2_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */
207 * Data structures used by the directory indexing feature
209 * Note: all of the multibyte integer fields are little endian.
213 * Note: dx_root_info is laid out so that if it should somehow get
214 * overlaid by a dirent the two low bits of the hash version will be
215 * zero. Therefore, the hash version mod 4 should never be 0.
216 * Sincerely, the paranoia department.
218 struct ext2_dx_root_info {
220 __u8 hash_version; /* 0 now, 1 at release */
221 __u8 info_length; /* 8 */
222 __u8 indirect_levels;
226 #define EXT2_HASH_LEGACY 0
227 #define EXT2_HASH_HALF_MD4 1
228 #define EXT2_HASH_TEA 2
229 #define EXT2_HASH_LEGACY_UNSIGNED 3 /* reserved for userspace lib */
230 #define EXT2_HASH_HALF_MD4_UNSIGNED 4 /* reserved for userspace lib */
231 #define EXT2_HASH_TEA_UNSIGNED 5 /* reserved for userspace lib */
233 #define EXT2_HASH_FLAG_INCOMPAT 0x1
235 struct ext2_dx_entry {
240 struct ext2_dx_countlimit {
246 * This goes at the end of each htree block.
248 struct ext2_dx_tail {
250 __le32 dt_checksum; /* crc32c(uuid+inum+dxblock) */
254 * Macro-instructions used to manage group descriptors
256 #define EXT2_MIN_DESC_SIZE 32
257 #define EXT2_MIN_DESC_SIZE_64BIT 64
258 #define EXT2_MAX_DESC_SIZE EXT2_MIN_BLOCK_SIZE
259 #define EXT2_DESC_SIZE(s) \
260 ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \
261 (s)->s_desc_size : EXT2_MIN_DESC_SIZE)
263 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
264 #define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
265 #define EXT2_CLUSTERS_PER_GROUP(s) (EXT2_SB(s)->s_clusters_per_group)
266 #define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
267 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
268 #define EXT2_MAX_BLOCKS_PER_GROUP(s) ((((unsigned) 1 << 16) - 8) * \
269 (EXT2_CLUSTER_SIZE(s) / \
271 #define EXT2_MAX_CLUSTERS_PER_GROUP(s) (((unsigned) 1 << 16) - 8)
272 #define EXT2_MAX_INODES_PER_GROUP(s) (((unsigned) 1 << 16) - \
273 EXT2_INODES_PER_BLOCK(s))
275 #define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
276 #define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
278 #define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_DESC_SIZE(s))
281 #define EXT2_GROUPS_TO_BLOCKS(s, g) ((blk64_t) EXT2_BLOCKS_PER_GROUP(s) * \
283 #define EXT2_GROUPS_TO_CLUSTERS(s, g) ((blk64_t) EXT2_CLUSTERS_PER_GROUP(s) * \
287 * Constants relative to the data blocks
289 #define EXT2_NDIR_BLOCKS 12
290 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
291 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
292 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
293 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
298 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
299 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
300 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
301 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
302 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
303 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
304 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
305 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
306 /* Reserved for compression usage... */
307 #define EXT2_DIRTY_FL 0x00000100
308 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
309 #define EXT2_NOCOMPR_FL 0x00000400 /* Access raw compressed data */
310 /* nb: was previously EXT2_ECOMPR_FL */
311 #define EXT4_ENCRYPT_FL 0x00000800 /* encrypted inode */
312 /* End compression flags --- maybe not all used */
313 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
314 #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */
315 #define EXT2_IMAGIC_FL 0x00002000
316 #define EXT3_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */
317 #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */
318 #define EXT2_DIRSYNC_FL 0x00010000 /* Synchronous directory modifications */
319 #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
320 #define EXT4_HUGE_FILE_FL 0x00040000 /* Set to each huge file */
321 #define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
322 #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */
323 /* EXT4_EOFBLOCKS_FL 0x00400000 was here */
324 #define FS_NOCOW_FL 0x00800000 /* Do not cow file */
325 #define EXT4_SNAPFILE_FL 0x01000000 /* Inode is a snapshot */
326 #define EXT4_SNAPFILE_DELETED_FL 0x04000000 /* Snapshot is being deleted */
327 #define EXT4_SNAPFILE_SHRUNK_FL 0x08000000 /* Snapshot shrink has completed */
328 #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data */
329 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
331 #define EXT2_FL_USER_VISIBLE 0x004BDFFF /* User visible flags */
332 #define EXT2_FL_USER_MODIFIABLE 0x004B80FF /* User modifiable flags */
338 /* Used for online resize */
339 struct ext2_new_group_input {
340 __u32 group; /* Group number for this data */
341 __u32 block_bitmap; /* Absolute block number of block bitmap */
342 __u32 inode_bitmap; /* Absolute block number of inode bitmap */
343 __u32 inode_table; /* Absolute block number of inode table start */
344 __u32 blocks_count; /* Total number of blocks in this group */
345 __u16 reserved_blocks; /* Number of reserved blocks in this group */
346 __u16 unused; /* Number of reserved GDT blocks in group */
349 struct ext4_new_group_input {
350 __u32 group; /* Group number for this data */
351 __u64 block_bitmap; /* Absolute block number of block bitmap */
352 __u64 inode_bitmap; /* Absolute block number of inode bitmap */
353 __u64 inode_table; /* Absolute block number of inode table start */
354 __u32 blocks_count; /* Total number of blocks in this group */
355 __u16 reserved_blocks; /* Number of reserved blocks in this group */
359 #ifdef __GNU__ /* Needed for the Hurd */
360 #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
363 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
364 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
365 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
366 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
367 #define EXT2_IOC_GETVERSION_NEW _IOR('f', 3, long)
368 #define EXT2_IOC_SETVERSION_NEW _IOW('f', 4, long)
369 #define EXT2_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long)
370 #define EXT2_IOC_GROUP_ADD _IOW('f', 8,struct ext2_new_group_input)
371 #define EXT4_IOC_GROUP_ADD _IOW('f', 8,struct ext4_new_group_input)
372 #define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
375 * Structure of an inode on the disk
378 __u16 i_mode; /* File mode */
379 __u16 i_uid; /* Low 16 bits of Owner Uid */
380 __u32 i_size; /* Size in bytes */
381 __u32 i_atime; /* Access time */
382 __u32 i_ctime; /* Inode change time */
383 __u32 i_mtime; /* Modification time */
384 __u32 i_dtime; /* Deletion Time */
385 __u16 i_gid; /* Low 16 bits of Group Id */
386 __u16 i_links_count; /* Links count */
387 __u32 i_blocks; /* Blocks count */
388 __u32 i_flags; /* File flags */
391 __u32 l_i_version; /* was l_i_reserved1 */
394 __u32 h_i_translator;
396 } osd1; /* OS dependent 1 */
397 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
398 __u32 i_generation; /* File version (for NFS) */
399 __u32 i_file_acl; /* File ACL */
400 __u32 i_size_high; /* Formerly i_dir_acl, directory ACL */
401 __u32 i_faddr; /* Fragment address */
405 __u16 l_i_file_acl_high;
406 __u16 l_i_uid_high; /* these 2 fields */
407 __u16 l_i_gid_high; /* were reserved2[0] */
408 __u16 l_i_checksum_lo; /* crc32c(uuid+inum+inode) */
412 __u8 h_i_frag; /* Fragment number */
413 __u8 h_i_fsize; /* Fragment size */
419 } osd2; /* OS dependent 2 */
423 * Permanent part of an large inode on the disk
425 struct ext2_inode_large {
426 __u16 i_mode; /* File mode */
427 __u16 i_uid; /* Low 16 bits of Owner Uid */
428 __u32 i_size; /* Size in bytes */
429 __u32 i_atime; /* Access time */
430 __u32 i_ctime; /* Inode Change time */
431 __u32 i_mtime; /* Modification time */
432 __u32 i_dtime; /* Deletion Time */
433 __u16 i_gid; /* Low 16 bits of Group Id */
434 __u16 i_links_count; /* Links count */
435 __u32 i_blocks; /* Blocks count */
436 __u32 i_flags; /* File flags */
439 __u32 l_i_version; /* was l_i_reserved1 */
442 __u32 h_i_translator;
444 } osd1; /* OS dependent 1 */
445 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
446 __u32 i_generation; /* File version (for NFS) */
447 __u32 i_file_acl; /* File ACL */
448 __u32 i_size_high; /* Formerly i_dir_acl, directory ACL */
449 __u32 i_faddr; /* Fragment address */
453 __u16 l_i_file_acl_high;
454 __u16 l_i_uid_high; /* these 2 fields */
455 __u16 l_i_gid_high; /* were reserved2[0] */
456 __u16 l_i_checksum_lo; /* crc32c(uuid+inum+inode) */
460 __u8 h_i_frag; /* Fragment number */
461 __u8 h_i_fsize; /* Fragment size */
467 } osd2; /* OS dependent 2 */
469 __u16 i_checksum_hi; /* crc32c(uuid+inum+inode) */
470 __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
471 __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
472 __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
473 __u32 i_crtime; /* File creation time */
474 __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
475 __u32 i_version_hi; /* high 32 bits for 64-bit version */
478 #define EXT4_INODE_CSUM_HI_EXTRA_END \
479 (offsetof(struct ext2_inode_large, i_checksum_hi) + sizeof(__u16) - \
480 EXT2_GOOD_OLD_INODE_SIZE)
482 #define i_dir_acl i_size_high
484 #define i_checksum_lo osd2.linux2.l_i_checksum_lo
486 #if defined(__KERNEL__) || defined(__linux__)
487 #define i_reserved1 osd1.linux1.l_i_reserved1
488 #define i_frag osd2.linux2.l_i_frag
489 #define i_fsize osd2.linux2.l_i_fsize
490 #define i_uid_low i_uid
491 #define i_gid_low i_gid
492 #define i_uid_high osd2.linux2.l_i_uid_high
493 #define i_gid_high osd2.linux2.l_i_gid_high
497 #define i_translator osd1.hurd1.h_i_translator
498 #define i_frag osd2.hurd2.h_i_frag;
499 #define i_fsize osd2.hurd2.h_i_fsize;
500 #define i_uid_high osd2.hurd2.h_i_uid_high
501 #define i_gid_high osd2.hurd2.h_i_gid_high
502 #define i_author osd2.hurd2.h_i_author
505 #endif /* defined(__KERNEL__) || defined(__linux__) */
507 #define inode_uid(inode) ((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
508 #define inode_gid(inode) ((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
509 #define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
510 #define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
515 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
516 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
517 #define EXT3_ORPHAN_FS 0x0004 /* Orphans being recovered */
520 * Misc. filesystem flags
522 #define EXT2_FLAGS_SIGNED_HASH 0x0001 /* Signed dirhash in use */
523 #define EXT2_FLAGS_UNSIGNED_HASH 0x0002 /* Unsigned dirhash in use */
524 #define EXT2_FLAGS_TEST_FILESYS 0x0004 /* OK for use on development code */
525 #define EXT2_FLAGS_IS_SNAPSHOT 0x0010 /* This is a snapshot image */
526 #define EXT2_FLAGS_FIX_SNAPSHOT 0x0020 /* Snapshot inodes corrupted */
527 #define EXT2_FLAGS_FIX_EXCLUDE 0x0040 /* Exclude bitmaps corrupted */
532 #define EXT2_MOUNT_CHECK 0x0001 /* Do mount-time checks */
533 #define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */
534 #define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */
535 #define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
536 #define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
537 #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
538 #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */
539 #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */
541 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
542 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
543 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
546 * Maximal mount counts between two filesystem checks
548 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
549 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
552 * Behaviour when detecting errors
554 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
555 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
556 #define EXT2_ERRORS_PANIC 3 /* Panic */
557 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
560 #define ext4_offsetof(TYPE,MEMBER) __builtin_offsetof(TYPE,MEMBER)
562 #define ext4_offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
565 /* Metadata checksum algorithms */
566 #define EXT2_CRC32C_CHKSUM 1
568 /* Encryption algorithms, key size and key reference len */
569 #define EXT4_ENCRYPTION_MODE_INVALID 0
570 #define EXT4_ENCRYPTION_MODE_AES_256_XTS 1
571 #define EXT4_ENCRYPTION_MODE_AES_256_GCM 2
572 #define EXT4_ENCRYPTION_MODE_AES_256_CBC 3
573 #define EXT4_ENCRYPTION_MODE_AES_256_CTS 4
575 #define EXT4_AES_256_XTS_KEY_SIZE 64
576 #define EXT4_AES_256_GCM_KEY_SIZE 32
577 #define EXT4_AES_256_CBC_KEY_SIZE 32
578 #define EXT4_AES_256_CTS_KEY_SIZE 32
579 #define EXT4_MAX_KEY_SIZE 64
581 #define EXT4_KEY_DESCRIPTOR_SIZE 8
582 #define EXT4_CRYPTO_BLOCK_SIZE 16
584 /* Password derivation constants */
585 #define EXT4_MAX_PASSPHRASE_SIZE 1024
586 #define EXT4_MAX_SALT_SIZE 256
587 #define EXT4_PBKDF2_ITERATIONS 0xFFFF
590 * Policy provided via an ioctl on the topmost directory. This
591 * structure is also in the kernel.
593 struct ext4_encryption_policy {
595 char contents_encryption_mode;
596 char filenames_encryption_mode;
598 char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
599 } __attribute__((__packed__));
601 struct ext4_encryption_key {
603 char raw[EXT4_MAX_KEY_SIZE];
605 } __attribute__((__packed__));
608 * Structure of the super block
610 struct ext2_super_block {
611 __u32 s_inodes_count; /* Inodes count */
612 __u32 s_blocks_count; /* Blocks count */
613 __u32 s_r_blocks_count; /* Reserved blocks count */
614 __u32 s_free_blocks_count; /* Free blocks count */
615 __u32 s_free_inodes_count; /* Free inodes count */
616 __u32 s_first_data_block; /* First Data Block */
617 __u32 s_log_block_size; /* Block size */
618 __u32 s_log_cluster_size; /* Allocation cluster size */
619 __u32 s_blocks_per_group; /* # Blocks per group */
620 __u32 s_clusters_per_group; /* # Fragments per group */
621 __u32 s_inodes_per_group; /* # Inodes per group */
622 __u32 s_mtime; /* Mount time */
623 __u32 s_wtime; /* Write time */
624 __u16 s_mnt_count; /* Mount count */
625 __s16 s_max_mnt_count; /* Maximal mount count */
626 __u16 s_magic; /* Magic signature */
627 __u16 s_state; /* File system state */
628 __u16 s_errors; /* Behaviour when detecting errors */
629 __u16 s_minor_rev_level; /* minor revision level */
630 __u32 s_lastcheck; /* time of last check */
631 __u32 s_checkinterval; /* max. time between checks */
632 __u32 s_creator_os; /* OS */
633 __u32 s_rev_level; /* Revision level */
634 __u16 s_def_resuid; /* Default uid for reserved blocks */
635 __u16 s_def_resgid; /* Default gid for reserved blocks */
637 * These fields are for EXT2_DYNAMIC_REV superblocks only.
639 * Note: the difference between the compatible feature set and
640 * the incompatible feature set is that if there is a bit set
641 * in the incompatible feature set that the kernel doesn't
642 * know about, it should refuse to mount the filesystem.
644 * e2fsck's requirements are more strict; if it doesn't know
645 * about a feature in either the compatible or incompatible
646 * feature set, it must abort and not try to meddle with
647 * things it doesn't understand...
649 __u32 s_first_ino; /* First non-reserved inode */
650 __u16 s_inode_size; /* size of inode structure */
651 __u16 s_block_group_nr; /* block group # of this superblock */
652 __u32 s_feature_compat; /* compatible feature set */
653 __u32 s_feature_incompat; /* incompatible feature set */
654 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
655 __u8 s_uuid[16]; /* 128-bit uuid for volume */
656 char s_volume_name[16]; /* volume name */
657 char s_last_mounted[64]; /* directory where last mounted */
658 __u32 s_algorithm_usage_bitmap; /* For compression */
660 * Performance hints. Directory preallocation should only
661 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
663 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
664 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
665 __u16 s_reserved_gdt_blocks; /* Per group table for online growth */
667 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
669 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
670 __u32 s_journal_inum; /* inode number of journal file */
671 __u32 s_journal_dev; /* device number of journal file */
672 __u32 s_last_orphan; /* start of list of inodes to delete */
673 __u32 s_hash_seed[4]; /* HTREE hash seed */
674 __u8 s_def_hash_version; /* Default hash version to use */
675 __u8 s_jnl_backup_type; /* Default type of journal backup */
676 __u16 s_desc_size; /* Group desc. size: INCOMPAT_64BIT */
677 __u32 s_default_mount_opts;
678 __u32 s_first_meta_bg; /* First metablock group */
679 __u32 s_mkfs_time; /* When the filesystem was created */
680 __u32 s_jnl_blocks[17]; /* Backup of the journal inode */
681 __u32 s_blocks_count_hi; /* Blocks count high 32bits */
682 __u32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/
683 __u32 s_free_blocks_hi; /* Free blocks count */
684 __u16 s_min_extra_isize; /* All inodes have at least # bytes */
685 __u16 s_want_extra_isize; /* New inodes should reserve # bytes */
686 __u32 s_flags; /* Miscellaneous flags */
687 __u16 s_raid_stride; /* RAID stride */
688 __u16 s_mmp_update_interval; /* # seconds to wait in MMP checking */
689 __u64 s_mmp_block; /* Block for multi-mount protection */
690 __u32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
691 __u8 s_log_groups_per_flex; /* FLEX_BG group size */
692 __u8 s_checksum_type; /* metadata checksum algorithm */
693 __u8 s_encryption_level; /* versioning level for encryption */
694 __u8 s_reserved_pad; /* Padding to next 32bits */
695 __u64 s_kbytes_written; /* nr of lifetime kilobytes written */
696 __u32 s_snapshot_inum; /* Inode number of active snapshot */
697 __u32 s_snapshot_id; /* sequential ID of active snapshot */
698 __u64 s_snapshot_r_blocks_count; /* reserved blocks for active
699 snapshot's future use */
700 __u32 s_snapshot_list; /* inode number of the head of the on-disk snapshot list */
701 #define EXT4_S_ERR_START ext4_offsetof(struct ext2_super_block, s_error_count)
702 __u32 s_error_count; /* number of fs errors */
703 __u32 s_first_error_time; /* first time an error happened */
704 __u32 s_first_error_ino; /* inode involved in first error */
705 __u64 s_first_error_block; /* block involved of first error */
706 __u8 s_first_error_func[32]; /* function where the error happened */
707 __u32 s_first_error_line; /* line number where error happened */
708 __u32 s_last_error_time; /* most recent time of an error */
709 __u32 s_last_error_ino; /* inode involved in last error */
710 __u32 s_last_error_line; /* line number where error happened */
711 __u64 s_last_error_block; /* block involved of last error */
712 __u8 s_last_error_func[32]; /* function where the error happened */
713 #define EXT4_S_ERR_END ext4_offsetof(struct ext2_super_block, s_mount_opts)
714 __u8 s_mount_opts[64];
715 __u32 s_usr_quota_inum; /* inode number of user quota file */
716 __u32 s_grp_quota_inum; /* inode number of group quota file */
717 __u32 s_overhead_blocks; /* overhead blocks/clusters in fs */
718 __u32 s_backup_bgs[2]; /* If sparse_super2 enabled */
719 __u8 s_encrypt_algos[4]; /* Encryption algorithms in use */
720 __u8 s_encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
721 __le32 s_lpf_ino; /* Location of the lost+found inode */
722 __le32 s_reserved[100]; /* Padding to the end of the block */
723 __u32 s_checksum; /* crc32c(superblock) */
726 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
729 * Codes for operating systems
731 #define EXT2_OS_LINUX 0
732 #define EXT2_OS_HURD 1
733 #define EXT2_OBSO_OS_MASIX 2
734 #define EXT2_OS_FREEBSD 3
735 #define EXT2_OS_LITES 4
740 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
741 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
743 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
744 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
746 #define EXT2_GOOD_OLD_INODE_SIZE 128
749 * Journal inode backup types
751 #define EXT3_JNL_BACKUP_BLOCKS 1
754 * Feature set definitions
757 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
758 ( EXT2_SB(sb)->s_feature_compat & (mask) )
759 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
760 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
761 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
762 ( EXT2_SB(sb)->s_feature_incompat & (mask) )
764 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
765 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
766 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
767 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
768 #define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010
769 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
770 #define EXT2_FEATURE_COMPAT_LAZY_BG 0x0040
771 /* #define EXT2_FEATURE_COMPAT_EXCLUDE_INODE 0x0080 not used, legacy */
772 #define EXT2_FEATURE_COMPAT_EXCLUDE_BITMAP 0x0100
773 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2 0x0200
776 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
777 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
778 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 not used */
779 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
780 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
781 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
782 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
783 #define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT 0x0080
784 #define EXT4_FEATURE_RO_COMPAT_QUOTA 0x0100
785 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC 0x0200
787 * METADATA_CSUM implies GDT_CSUM. When METADATA_CSUM is set, group
788 * descriptor checksums use the same algorithm as all other data
789 * structures' checksums.
791 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
792 #define EXT4_FEATURE_RO_COMPAT_REPLICA 0x0800
793 #define EXT4_FEATURE_RO_COMPAT_READONLY 0x1000
794 #define EXT4_FEATURE_RO_COMPAT_PROJECT 0x2000 /* Project quota */
797 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
798 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
799 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
800 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
801 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
802 #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040
803 #define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
804 #define EXT4_FEATURE_INCOMPAT_MMP 0x0100
805 #define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
806 #define EXT4_FEATURE_INCOMPAT_EA_INODE 0x0400
807 #define EXT4_FEATURE_INCOMPAT_DIRDATA 0x1000
808 /* 0x2000 was EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM but this was never used */
809 #define EXT4_FEATURE_INCOMPAT_LARGEDIR 0x4000 /* >2GB or 3-lvl htree */
810 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA 0x8000 /* data in inode */
811 #define EXT4_FEATURE_INCOMPAT_ENCRYPT 0x10000
813 #define EXT4_FEATURE_COMPAT_FUNCS(name, ver, flagname) \
814 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
816 return ((EXT2_SB(sb)->s_feature_compat & \
817 EXT##ver##_FEATURE_COMPAT_##flagname) != 0); \
819 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
821 EXT2_SB(sb)->s_feature_compat |= \
822 EXT##ver##_FEATURE_COMPAT_##flagname; \
824 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
826 EXT2_SB(sb)->s_feature_compat &= \
827 ~EXT##ver##_FEATURE_COMPAT_##flagname; \
830 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, ver, flagname) \
831 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
833 return ((EXT2_SB(sb)->s_feature_ro_compat & \
834 EXT##ver##_FEATURE_RO_COMPAT_##flagname) != 0); \
836 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
838 EXT2_SB(sb)->s_feature_ro_compat |= \
839 EXT##ver##_FEATURE_RO_COMPAT_##flagname; \
841 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
843 EXT2_SB(sb)->s_feature_ro_compat &= \
844 ~EXT##ver##_FEATURE_RO_COMPAT_##flagname; \
847 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, ver, flagname) \
848 static inline int ext2fs_has_feature_##name(struct ext2_super_block *sb) \
850 return ((EXT2_SB(sb)->s_feature_incompat & \
851 EXT##ver##_FEATURE_INCOMPAT_##flagname) != 0); \
853 static inline void ext2fs_set_feature_##name(struct ext2_super_block *sb) \
855 EXT2_SB(sb)->s_feature_incompat |= \
856 EXT##ver##_FEATURE_INCOMPAT_##flagname; \
858 static inline void ext2fs_clear_feature_##name(struct ext2_super_block *sb) \
860 EXT2_SB(sb)->s_feature_incompat &= \
861 ~EXT##ver##_FEATURE_INCOMPAT_##flagname; \
864 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc, 2, DIR_PREALLOC)
865 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes, 2, IMAGIC_INODES)
866 EXT4_FEATURE_COMPAT_FUNCS(journal, 3, HAS_JOURNAL)
867 EXT4_FEATURE_COMPAT_FUNCS(xattr, 2, EXT_ATTR)
868 EXT4_FEATURE_COMPAT_FUNCS(resize_inode, 2, RESIZE_INODE)
869 EXT4_FEATURE_COMPAT_FUNCS(dir_index, 2, DIR_INDEX)
870 EXT4_FEATURE_COMPAT_FUNCS(lazy_bg, 2, LAZY_BG)
871 EXT4_FEATURE_COMPAT_FUNCS(exclude_bitmap, 2, EXCLUDE_BITMAP)
872 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2, 4, SPARSE_SUPER2)
874 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super, 2, SPARSE_SUPER)
875 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file, 2, LARGE_FILE)
876 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file, 4, HUGE_FILE)
877 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum, 4, GDT_CSUM)
878 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink, 4, DIR_NLINK)
879 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize, 4, EXTRA_ISIZE)
880 EXT4_FEATURE_RO_COMPAT_FUNCS(has_snapshot, 4, HAS_SNAPSHOT)
881 EXT4_FEATURE_RO_COMPAT_FUNCS(quota, 4, QUOTA)
882 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc, 4, BIGALLOC)
883 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum, 4, METADATA_CSUM)
884 EXT4_FEATURE_RO_COMPAT_FUNCS(replica, 4, REPLICA)
885 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly, 4, READONLY)
886 EXT4_FEATURE_RO_COMPAT_FUNCS(project, 4, PROJECT)
888 EXT4_FEATURE_INCOMPAT_FUNCS(compression, 2, COMPRESSION)
889 EXT4_FEATURE_INCOMPAT_FUNCS(filetype, 2, FILETYPE)
890 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery, 3, RECOVER)
891 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev, 3, JOURNAL_DEV)
892 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg, 2, META_BG)
893 EXT4_FEATURE_INCOMPAT_FUNCS(extents, 3, EXTENTS)
894 EXT4_FEATURE_INCOMPAT_FUNCS(64bit, 4, 64BIT)
895 EXT4_FEATURE_INCOMPAT_FUNCS(mmp, 4, MMP)
896 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg, 4, FLEX_BG)
897 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode, 4, EA_INODE)
898 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata, 4, DIRDATA)
899 EXT4_FEATURE_INCOMPAT_FUNCS(largedir, 4, LARGEDIR)
900 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data, 4, INLINE_DATA)
901 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt, 4, ENCRYPT)
903 #define EXT2_FEATURE_COMPAT_SUPP 0
904 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
905 EXT4_FEATURE_INCOMPAT_MMP)
906 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
907 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
908 EXT4_FEATURE_RO_COMPAT_DIR_NLINK| \
909 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
912 * Default values for user and/or group using reserved blocks
914 #define EXT2_DEF_RESUID 0
915 #define EXT2_DEF_RESGID 0
918 * Default mount options
920 #define EXT2_DEFM_DEBUG 0x0001
921 #define EXT2_DEFM_BSDGROUPS 0x0002
922 #define EXT2_DEFM_XATTR_USER 0x0004
923 #define EXT2_DEFM_ACL 0x0008
924 #define EXT2_DEFM_UID16 0x0010
925 #define EXT3_DEFM_JMODE 0x0060
926 #define EXT3_DEFM_JMODE_DATA 0x0020
927 #define EXT3_DEFM_JMODE_ORDERED 0x0040
928 #define EXT3_DEFM_JMODE_WBACK 0x0060
929 #define EXT4_DEFM_NOBARRIER 0x0100
930 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
931 #define EXT4_DEFM_DISCARD 0x0400
932 #define EXT4_DEFM_NODELALLOC 0x0800
935 * Structure of a directory entry
937 #define EXT2_NAME_LEN 255
939 struct ext2_dir_entry {
940 __u32 inode; /* Inode number */
941 __u16 rec_len; /* Directory entry length */
942 __u16 name_len; /* Name length */
943 char name[EXT2_NAME_LEN]; /* File name */
947 * The new version of the directory entry. Since EXT2 structures are
948 * stored in intel byte order, and the name_len field could never be
949 * bigger than 255 chars, it's safe to reclaim the extra byte for the
952 * This structure is deprecated due to endianity issues. Please use struct
953 * ext2_dir_entry and accessor functions
954 * ext2fs_dirent_name_len
955 * ext2fs_dirent_set_name_len
956 * ext2fs_dirent_file_type
957 * ext2fs_dirent_set_file_type
958 * to get and set name_len and file_type fields.
960 struct ext2_dir_entry_2 {
961 __u32 inode; /* Inode number */
962 __u16 rec_len; /* Directory entry length */
963 __u8 name_len; /* Name length */
965 char name[EXT2_NAME_LEN]; /* File name */
969 * This is a bogus directory entry at the end of each leaf block that
972 struct ext2_dir_entry_tail {
973 __u32 det_reserved_zero1; /* Pretend to be unused */
974 __u16 det_rec_len; /* 12 */
975 __u16 det_reserved_name_len; /* 0xDE00, fake namelen/filetype */
976 __u32 det_checksum; /* crc32c(uuid+inode+dirent) */
980 * Ext2 directory file types. Only the low 3 bits are used. The
981 * other bits are reserved for now.
983 #define EXT2_FT_UNKNOWN 0
984 #define EXT2_FT_REG_FILE 1
985 #define EXT2_FT_DIR 2
986 #define EXT2_FT_CHRDEV 3
987 #define EXT2_FT_BLKDEV 4
988 #define EXT2_FT_FIFO 5
989 #define EXT2_FT_SOCK 6
990 #define EXT2_FT_SYMLINK 7
992 #define EXT2_FT_MAX 8
995 * Annoyingly, e2fsprogs always swab16s ext2_dir_entry.name_len, so we
996 * have to build ext2_dir_entry_tail with that assumption too. This
997 * constant helps to build the dir_entry_tail to look like it has an
998 * "invalid" file type.
1000 #define EXT2_DIR_NAME_LEN_CSUM 0xDE00
1003 * EXT2_DIR_PAD defines the directory entries boundaries
1005 * NOTE: It must be a multiple of 4
1007 #define EXT2_DIR_ENTRY_HEADER_LEN 8
1008 #define EXT2_DIR_PAD 4
1009 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
1010 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + \
1011 EXT2_DIR_ENTRY_HEADER_LEN + \
1016 * Constants for ext4's extended time encoding
1018 #define EXT4_EPOCH_BITS 2
1019 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
1020 #define EXT4_NSEC_MASK (~0UL << EXT4_EPOCH_BITS)
1023 * This structure is used for multiple mount protection. It is written
1024 * into the block number saved in the s_mmp_block field in the superblock.
1025 * Programs that check MMP should assume that if SEQ_FSCK (or any unknown
1026 * code above SEQ_MAX) is present then it is NOT safe to use the filesystem,
1027 * regardless of how old the timestamp is.
1029 * The timestamp in the MMP structure will be updated by e2fsck at some
1030 * arbitary intervals (start of passes, after every few groups of inodes
1031 * in pass1 and pass1b). There is no guarantee that e2fsck is updating
1032 * the MMP block in a timely manner, and the updates it does are purely
1033 * for the convenience of the sysadmin and not for automatic validation.
1035 * Note: Only the mmp_seq value is used to determine whether the MMP block
1036 * is being updated. The mmp_time, mmp_nodename, and mmp_bdevname
1037 * fields are only for informational purposes for the administrator,
1038 * due to clock skew between nodes and hostname HA service takeover.
1040 #define EXT4_MMP_MAGIC 0x004D4D50U /* ASCII for MMP */
1041 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
1042 #define EXT4_MMP_SEQ_FSCK 0xE24D4D50U /* mmp_seq value when being fscked */
1043 #define EXT4_MMP_SEQ_MAX 0xE24D4D4FU /* maximum valid mmp_seq value */
1045 /* Not endian-annotated; it's swapped at read/write time */
1047 __u32 mmp_magic; /* Magic number for MMP */
1048 __u32 mmp_seq; /* Sequence no. updated periodically */
1049 __u64 mmp_time; /* Time last updated */
1050 char mmp_nodename[64]; /* Node which last updated MMP block */
1051 char mmp_bdevname[32]; /* Bdev which last updated MMP block */
1052 __u16 mmp_check_interval; /* Changed mmp_check_interval */
1054 __u32 mmp_pad2[226];
1055 __u32 mmp_checksum; /* crc32c(uuid+mmp_block) */
1059 * Default interval for MMP update in seconds.
1061 #define EXT4_MMP_UPDATE_INTERVAL 5
1064 * Maximum interval for MMP update in seconds.
1066 #define EXT4_MMP_MAX_UPDATE_INTERVAL 300
1069 * Minimum interval for MMP checking in seconds.
1071 #define EXT4_MMP_MIN_CHECK_INTERVAL 5
1074 * Minimum size of inline data.
1076 #define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__u32) * EXT2_N_BLOCKS))
1079 * Size of a parent inode in inline data directory.
1081 #define EXT4_INLINE_DATA_DOTDOT_SIZE (4)
1083 #endif /* _LINUX_EXT2_FS_H */